Earth, Atmosphere & Environment Sciences

Title :

Roof rock reinforcement system (R3S) for mine roadways intersection under varying geomining conditions

Area of research :

Earth, Atmosphere & Environment Sciences

Focus area :

Mine safety

Principal Investigator :

Dr Ranjan Kumar, Scientist, CSIR-Central Institute of Mining and Fuel Research (CSIR-CIMFR), Dhanbad

Timeline Start Year :


Timeline End Year :


Contact info :


Executive Summary :

Objective: The critical analysis of the latest accident data published by Directorate General of Mine Safety (2016-17), it is revealed that 50% of the fatal accidents occurred in galleries width>4.51m in Indian underground coal mines. The mine roadways intersections, having width>4.51m, present an elevated risk of instability due to a decrease in roof rock strength. The reinforcement of roof rocks is used to increase the apparent strength of the immediate roof zone. However, the existing methods cause the over-design of the reinforcement system and found ineffective in the stabilization of intersection roof strata at greater depths and for a longer duration.Inview of above this project aims to develop a novel Roof Rock Reinforcement System (R3S) for the mine roadways intersection under varying geomining conditions.

Summary: The rock reinforcement systems to stabilize mine roadways intersections are designed using Factor of Safety (FoS), which is a ratio of the reinforcement resistance to the roof rock-load of overlying immediate strata. The roof rock-load over the mine roadways intersection in Indian coal mines is estimated empirically by Rock Mass Rating (RMR) developed at CSIR-CIMFR. However, this method is applicable only to the development stage. There is no specific empirical method for designing rock reinforcement during depillaring operation. Further, the numerical approach applied in designing rock reinforcement considers continuum rock layers to determine rock load height. In reality, the roof strata are full of discontinuities and geological anomalies. Therefore, an effective roof rock reinforcement system is highly needed for stable roof strata over the mine roadways intersections with optimum reinforcement elements to enhance safety and productivity in Indian coal mines. In this direction, this project aims to develop a novel Roof Rock Reinforcement System (R3S) for the mine roadways intersection under varying geomining conditions. The design methodology includes the characterization of stable and instable mine roadway intersections, identification of key parameters of instability, numerical modeling and parametric studied of the R3S designs using FLAC3D, 3DEC, ABAQUS, and field validations at three mine-sites. Finally, a standard guideline will be developed to optimize the R3S for the effective stabilization of Indian mine roadway intersections under varying geomining conditions. The envisaged scientific outputs of this project are estimating the effective span of the intersection, predicting load transfer mechanisms over the roof strata, and optimizing the combinations of short and long rock reinforcement elements. Additionally, this project will enable CSIR-CIMFR to serve the mining industry by improving the safety at mine roadways intersection, reducing the costs of reinforcement, and widening the intersection span for higher mechanization and coal production in the country.

Organizations involved